Gosh- here is what I think:
An internal bi-wire has a single connection at the amp end and a double connection at the speaker end all housed in a single cable.
An external bi-wire or "shotgun" cable has two separate runs of cable with a single connection (a '+' & a '-') at the amp end and each separate run of cable has a '+' & '-' at the speaker end. So you have four runs of cable total. If you break the single connection at the amp end you could single wire two sets of speakers.
I think the term external biwire is aptly descriptive. Where the term "shotgun" came from is anybody's guess.
An internal bi-wire has a single connection at the amp end and a double connection at the speaker end all housed in a single cable.
An external bi-wire or "shotgun" cable has two separate runs of cable with a single connection (a '+' & a '-') at the amp end and each separate run of cable has a '+' & '-' at the speaker end. So you have four runs of cable total. If you break the single connection at the amp end you could single wire two sets of speakers.
I think the term external biwire is aptly descriptive. Where the term "shotgun" came from is anybody's guess.